Tool Name	Fill Sinks (Wang & Liu)
Tool ID	4
Library ID	ta_preprocessor
Version	1.0
Author(s)	Copyrights (c) 2007 by Volker Wichmann

Description

This tool uses an algorithm proposed by Wang & Liu to identify and fill surface depressions in digital elevation models.
The method was enhanced to allow the creation of hydrologic sound elevation models, i.e. not only to fill the depression(s) but also to preserve a downward slope along the flow path. If desired, this is accomplished by preserving a minimum slope gradient (and thus elevation difference) between cells.
This is the fully featured version of the tool creating a depression less DEM, a flow path grid and a grid with watershed basins. If you encounter problems processing large data sets (e.g. LIDAR data) with this tool try the basic version (Fill Sinks XXL).

References

Wang, L., Liu, H. (2006): An efficient method for identifying and filling surface depressions in digital elevation models for hydrologic analysis and modelling. International Journal of Geographical Information Science, Vol. 20, No. 2, 193-213.

Parameters

Name	Type	Identifier	Description	Constraints
Input
DEM	grid, input	ELEV	Digital elevation model
Output
Filled DEM	grid, output	FILLED	Depression-free digital elevation model
Flow Directions	grid, output	FDIR	Computed flow directions, 0=N, 1=NE, 2=E, ... 7=NW
Watershed Basins	grid, output	WSHED	Delineated watershed basins
Options
Minimum Slope [Degree]	floating point number	MINSLOPE	Minimum slope gradient to preserve from cell to cell; with a value of zero sinks are filled up to the spill elevation (which results in flat areas). Unit [Degree]	Minimum: 0.000000 Default: 0.100000